Embodiments of the present invention generally relate to an electrical connector for use with point-to-point serial data streams and particularly to connectors that compensate for signal loss within point-to-point data streams.
In the past, right angle connectors have been provided for connection between printed circuit boards. The right angled connectors may use a large plurality of receiving terminals oriented at a right angle to an equally large plurality of pins. One common implementation of such connectors is to join daughter cards with a backplane in a data transmission system. In conventional systems, connectors have been proposed that are able to support bi-directional data streams arranged in a multi-drop bus configuration. These conventional bi-directional data streams conveyed signals in opposite directions over each individual trace through the connector.
Existing multi-drop bus architectures utilize a single driver or transmitter, such as arranged on one daughter card that transmits a signal along a trace along the backplane. This trace on the backplane is tapped at multiple locations to feed a plurality of receivers on an equal plurality of daughter cards. Hence, a single transceiver (transmitter/receiver) on a first daughter card may communicate along a common trace over the backplane to a plurality of transceivers arranged on separate other daughter cards.
However, conventional configurations have experienced certain disadvantages at high data rates. As the data rate increases, the high frequency components of the signal experience more loss and more reflection within the backplane and connector assemblies interconnecting the daughter cards. Signal degradation increases as the number of daughter cards increases that tap into a single trace along the backplane. For example, as the data rate increases, each signal trace, within an individual connector extending to the daughter cards, begins to function more as a transmission line. As the traces extending to each daughter card exhibit more characteristics of transmission lines, the energy conveyed along the backplane divides at each point where a daughter card connector tapped into a trace on the backplane. The more times the energy is split, the more reflection and loss is experienced. Conventional connectors have attempted to reduce the negative effects of the multi-drop bus architecture by providing a bus arbitration logic chip as a switch within a bi-directional communications link. One example of such a configuration is illustrated in U.S. Pat. No. 6,168,469.
However, bi-directional communication format and multi-drop bus architectures continue to exhibit signal degradation and reliance problems. Hence, bi-directional communications and multi-drop bus architectures are becoming less frequently used and are no longer desirable in certain applications. Instead, an entirely different communications format and connector architecture are now being advanced, namely serial communication over a point-to-point architecture. In serial communication over a point-to-point architecture, each transmitter is uniquely associated with a single receiver to afford a distinct and separate communications link therebetween. In a point-to-point architecture, only as single daughter card taps into a single trace along the backplane. Each transmitter and receiver upon each daughter card is afforded a dedicated communications path and dedicated traces both within the connector and along the backplane. Conventional approaches, such as described in the '469 patent, are not useful nor afford any advantage in point-to-point architectures.
Hence, a need remains for an improved connector assembly designed for a point-to-point architecture that conveys serial data streams.